From c8a41c6afa27b8c3f61622dfd882b912da9d6721 Mon Sep 17 00:00:00 2001
From: Denis Kenzior <denkenz@gmail.com>
Date: Tue, 27 Aug 2019 17:41:19 -0500
Subject: [PATCH] mac80211: Don't memset RXCB prior to PAE intercept
Git-commit: c8a41c6afa27b8c3f61622dfd882b912da9d6721
Patch-mainline: v5.3-rc7
References: bsc#1111666

In ieee80211_deliver_skb_to_local_stack intercepts EAPoL frames if
mac80211 is configured to do so and forwards the contents over nl80211.
During this process some additional data is also forwarded, including
whether the frame was received encrypted or not.  Unfortunately just
prior to the call to ieee80211_deliver_skb_to_local_stack, skb->cb is
cleared, resulting in incorrect data being exposed over nl80211.

Fixes: 018f6fbf540d ("mac80211: Send control port frames over nl80211")
Cc: stable@vger.kernel.org
Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Link: https://lore.kernel.org/r/20190827224120.14545-2-denkenz@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 net/mac80211/rx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 3c1ab870fefe..7c4aeac006fb 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2452,6 +2452,8 @@ static void ieee80211_deliver_skb_to_local_stack(struct sk_buff *skb,
 		cfg80211_rx_control_port(dev, skb, noencrypt);
 		dev_kfree_skb(skb);
 	} else {
+		memset(skb->cb, 0, sizeof(skb->cb));
+
 		/* deliver to local stack */
 		if (rx->napi)
 			napi_gro_receive(rx->napi, skb);
@@ -2546,8 +2548,6 @@ ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
 
 	if (skb) {
 		skb->protocol = eth_type_trans(skb, dev);
-		memset(skb->cb, 0, sizeof(skb->cb));
-
 		ieee80211_deliver_skb_to_local_stack(skb, rx);
 	}
 
-- 
2.16.4